def calculateDues(book_id, token=None, uid=None):
'''
Function to calculate the dues for a student given the student token/ USN and the book id
We take both token and USN because if the admin makes the request when viewing a students page then we need to be able to
handle that as well
params:
book_id : <str> The books ID
token : <str> Default None , The token of the user making the request
uid : <str> The USN of the student to calculate the due for
returns:
<str> --- if theres no due
<int> The amount due if books are due
'''
# get the token from the tokencollection
userData = tokenCollection.find_one({"token": token})
# if the token belongs to an admin then the borrow data needs to come from the student ie students user id
if userData['_id'] == "Admin":
userData = {"_id": uid}
# get the borrow object
borrowObj = borrowsCollection.find_one({
"User": userData['_id'],
"BookID": book_id
})
# get the number of days overdue
daysDue = (
datetime.now().replace(minute=0, second=0, hour=0, microsecond=0) -
borrowObj['DueDate'].replace(
minute=0, second=0, hour=0, microsecond=0)).days
if daysDue <= 0:
return "--"
else:
return format_price(5 * daysDue)
def decorated_function(*args, **kwargs):
'''
Function to wrap the passed function
params:
*args: <args> The arguments
**kwargs : <kwargs> The Kwargs
returns:
<f::returnType> The Return of the passed function
'''
# If the token isnt available, redirect to login
if "token" not in session or not session['token']:
return redirect(url_for("loginHandler"))
token = session['token']
# If the tokendata is not present redirect to login
tokenData = tokenCollection.find_one({"token": token}, {"token": 0})
if not tokenData:
return redirect(url_for("loginHandler"))
# If the user data does not exist, redirect to login
userData = usersCollection.find_one({"_id": tokenData['_id']},
{"Type": 1})
if not userData:
return redirect(url_for("index"))
# If the type is Stuent we redirect to index ie home page
if userData['Type'] == "Student":
return redirect(url_for("index"))
return f(*args, **kwargs)
def userLogin(userData):
'''
Function to check the users credentials and login.
params:
userData : <dict> Dict containing the user details ie password and usn
returns:
<dict> {status:True,message:True,token:<str:token string>} if success
{status:False,message:Error Message} if failure
'''
# Check if USN and password fields are non-empty
# if empty return the error
if not userData['USN']:
return {'status':False,'message':"Please Enter USN"}
if not userData['password']:
return {'status':False,'message':"Please Enter password"}
# Check if the user token exists or not in the token collection
# if it exists it means the user is already logged in
userToken = tokenCollection.find_one({"_id":userData['USN']})
if userToken:
return {'status':True,'message':"User logged in","token":userToken['token']}
try:
# Fetch the users auth data
userAuth = authCollection.find_one({"_id":userData['USN']})
# handle connection failure
except ConnectionFailure:
return {'status':False,'message':"Could not connect to database"}
# if the auth data does not exist , error out
if not userAuth:
return {'status':False,'message':"User does not exist"}
# calculate the the hash of the given password + the salt
passHash = sha256((userData['password']+userAuth['salt']).encode()).hexdigest()
# if it matches , login successfully
if passHash == userAuth['passHash']:
token = str(uuid4())
# insert the token and the id into the token collection
try:
tokenCollection.insert_one({
"_id":userData['USN'],
"token":token
})
except DuplicateKeyError:
return {"status":True,'message':"User already logged in","token":token}
return {"status":True,'message':"User Logged in","token":token}
# if the hash does not match we error out
else:
return {'status':False,'message':"Incorrect USN or password"}
def checkIfReserved(token, book_id):
'''
Function to check if the book has been reserved by the current user
params:
token: <str> The token of the current user
book_id : <str> The ID of the book
returns:
<bool> True, if reserved
False if not reserved
'''
tokenObj = tokenCollection.find_one({"token": token})
borrowObj = borrowsCollection.find_one({
"User": tokenObj['_id'],
"BookID": book_id
})
if not borrowObj:
return False
else:
return True
def getDueDate(token, book_id, uid=None):
'''
Function to get the due date for the given book for the given user
params:
token : <str> The token of the user making the request
book_id : <str> The ID of the book
returns:
<str> Date in yyyy-mm-dd format
'''
# get the token from the tokencollection
tokenObj = tokenCollection.find_one({"token": token})
# if the token belongs to an admin then the borrow data needs to come from the student ie students user id
if tokenObj['_id'] == "Admin":
tokenObj = {"_id": uid}
borrowObj = borrowsCollection.find_one({
"User": tokenObj['_id'],
"BookID": book_id
})
duedate = borrowObj['DueDate'].strftime("%Y-%m-%d")
return duedate
def getUserFromToken(token):
'''
Function to get the user data for a particular user based on the token
params:
token : <str> The Users token
returns:
<dict> {status:True,message:<dict: User data>,borrows:<List(dict): list of all borrowed books >} if success
{status:False,message:Error Message} if failure
'''
try:
# get the token object from the token collection
tokenData = tokenCollection.find_one({"token":token})
# handle connection failure
except ConnectionFailure:
return {'status':False,'message':"Unable to connnect to database"}
# if the token obj does not exist, then return an error
if not tokenData:
return {'status':False,'message':"Token does not exist, please refresh/logout and log back in"}
# get the user associated with that token
userId = tokenData['_id']
try:
# get the userdata based on that token
userData = usersCollection.find_one({"_id":userId})
# handle connection faliure
except ConnectionFailure:
return {'status':False,'message':"Unable to connnect to database"}
# if user obj does not exist throw an error
if not userData:
return {'status':False,'message':"User data does not exist"}
borrowData = getUsersBorrowedBooks(userId)
if not borrowData['status']:
return {'status':False,'message':"Unable to fetch user data"}
borrowData = borrowData['message']
# return the user object
return {'status':True,'message':userData,'borrows':borrowData}
def isAdmin(token):
'''
Function to check if the token of the user is an admin token or not
params:
token :<str> The token of the user making the request
returns:
<bool> True if admin
False if not admin
'''
tokenData = tokenCollection.find_one({"token": token}, {"token": 0})
if not tokenData:
return False
userData = usersCollection.find_one({"_id": tokenData['_id']},
{"Type": 1})
if not userData:
return False
if userData['Type'] == "Student":
return False
else:
return True
def reserveBook(book_id,book_name,token):
'''
Function to reserve a book
params:
book_id : <str> The book id for the book being borrowed
book_name : <str> The book Name
token : <str> The token of the user making the request
'''
tokenObj = tokenCollection.find_one({"token":token})
if not tokenObj:
return {'status':False,'message':"Unable to find token, please logout and log back in"}
# generate the book borrow object
borrowObj = {
"BookName":book_name,
"BorrowedOn":datetime.now(),
"DueDate":(datetime.now() + timedelta(days=10)),
"ReturnedOn":None,
"User":tokenObj['_id'],
"BookID":book_id
}
# find if the book is in stock before inserting the borrow data into the database
book_stock = booksCollection.find_one({"_id":book_id},{"Stock":1})
# if not in stock throw an error
if book_stock['Stock']<=0:
return {'status':False,'message':"Book is out Stock"}
# if in stock then update the count of that book and insert the borrow obj
booksCollection.update_one({"_id":book_id},{"$inc":{"Stock":-1}})
# insert the object
try:
borrowsCollection.insert_one(borrowObj)
except ConnectionFailure:
booksCollection.update_one({"_id":book_id},{"$inc":{"Stock":1}})
return {'status':False,'message':"Unable to connect to database"}
return {'status':True,'message':"Book reserved"}
